FYI: the NMNH Lepidoptera larval collection used to be in Isopropyl with a small amount of glycerine "to keep the larvae soft."
 This policy changed when the collection was moved to the East Court and the entire collection was transferred to new vials and jars with 70% ethanol.

-----Original Message-----
From: Entomological Collections Network Listserve [mailto:[log in to unmask]] On Behalf Of Furth, David
Sent: Wednesday, July 18, 2018 6:32 PM
To: [log in to unmask]
Subject: Re: glycerol (and adhesive follow-up)

At Yale's Peabody Museum in the 1950s Charles Remington started adding a small (ca. 2%) of glycerine to all  specimen vials of ethanol (70%) to minimize desiccation damage - I witnessed that it worked.  I have used it in polyethylene genitalia/pin vials since 1972 with no visible damage or effects.
When I came to the Smithsonian Institution in 1994 Jonathan Coddington told me (I believe anecdotally) that glycerine had a long-term clearing effect on chitin, but I do not know if that is published anywhere.  However, also remember that glycerine is very hygroscopic.

Attached is part of a 2005 publication by our conservator (Cathy Hawks & Sturman) that may be of interest about testing glycerine for the acidic effects.

David G. Furth, Ph.D.
Emeritus Collections Manager & Research Associate Department of Entomology MRC 165, P.O. Box 37012 National Museum of Natural History Smithsonian Institution Washington, D. C. 20013-7012  USA
Phone: 202-633-0990
Fax: 202-786-2894
Email: [log in to unmask]

-----Original Message-----
From: Entomological Collections Network Listserve <[log in to unmask]> On Behalf Of Andy Deans
Sent: Wednesday, July 18, 2018 2:30 PM
To: [log in to unmask]
Subject: glycerol (and adhesive follow-up)

Hi all,

Does anyone know the history of glycerol / glycerin / glycerine use in entomology, for storing genitalia, etc.? I see references from the 1950s at least, some with additives like chloral hydrate and (yikes!) arsenic. Does anyone know how stable glycerol alone is over the long term? I heard anecdotally that there are specimens more than 100 years old that have been stored in glycerol. My impression is that these older specimens are mostly cuticle - the soft bits having been digested away with KOH. Would soft tissues preserve well in glycerol alone? Thanks for any help!

Also, thanks for your responses to the survey about adhesives. I have been researching different classes of adhesives and now have a manuscript to be shared shortly. The results will also be presented at the meeting in Vancouver. More soon ... but I should put at least this advise out there now: We really should stop using clear nail polish and Elmer's! They are NOT archival.

Andy Deans
Frost Entomological Museum
Penn State

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